I have a 2001 chevy venture (254,000 miles) that has me baffled. It has been a great van but it started about a month ago sputtering and bucking and numerous times shutting off. Most times the engine light would NOT come on. It would get the hiccoughs and start bucking like someone learning to drive a stick shift for the first time. Once it sputtered hard enough to throw off the serpentine belt. Thank God I put a new timing belt on it last year when I redone the intake manifold gasket. Now its not shutting off but it has only about half the power it should and the engine light is starting to come on more often. It bogs down and then it will try to go then bog down again. The engine light blinks for about 20 seconds then stops and goes out. When the engine light is on and stays on the code most often says system too lean, and a egr flow insufficient. It does have a vacuum leak in the hose going to the egr. Have ordered that, hasn’t come in yet. Gas mileage is horrible. I have done new plugs, fuel filter and cleaned the K&N air filter. Someone suggested the catalytic converter. I dumped in a bottle of ‘Cata-cleanse’ from Autozone. No difference. A friend of mine had a venture doing the exact same thing. It was in the shop for 6mo with no luck. But his straightened out on its own and is running good now. I really don’t feel like waiting 6mo to see if this will straighten out. Any tho’ts? Thanks!

oiled air filters, such as K&N, have been known to contaminate mass airflow sensors. Here’s what might be going on. The mass airflow sensor is now contaminated, and seeing a false lean condition. The PCM wants to correct this supposed lean condition, so it commands the injectors to stay open a lot longer. That could mean increased fuel consumption

Just a thought

If it were my van, I’d start fresh with a factory air filter set up, replace those leaking hoses, and take it from there

By the way, a flashing check engine light means a severe misfire, severe enough to possibly damage the catalytic converter

May want to hook up a back pressure gauge. The cat may already be partially plugged. The back pressure gauge will either confirm or deny this

Hi. Thank you all. My friend who had similar troubles with his van said that they never diagnosed the problem on his venture, it just seemingly straightened out on its own, so he’s curious too as to what is going on. Yesterday I unplugged the vacuum line going to the fuel press regulator and nothing changed in performance. So I guess I’ll take it to a shop to test pressure since I don’t have a fuel pressure gauge. I did think of the mass air flow sensor, but it’s not throwing a code. I did unplug it while the van was running. No change in the idle, and it still didn’t throw a MAF code. EGR throws a code now that I got the vacuum leak fixed going to the EGR. Thanks! Matt